Plutella xylostella L. (cabbage caterpillar) is one of the most damaging main pests on Brassica olerace ae (cabbage flower) plants. Synthetic pesticides can control pests quickly and are very practical in their use. However, it leaves damage to the environment, especially soil by killing soil microorganisms that are useful for plant growth. Therefore, an alternative control that is environmentally friendly and effective is needed to reduce the intensity of pest attacks. The aim of this study was to determine the most effective concentration of the tobacco stem waste extract, Nicotiana tabacum L, to suppress the intensity of P. xylostella attack on cauliflower plants. This research was conducted in Kp. Cipariuk, Ds. Srirahayu district. Cikancung Kab. Bandung West Java Province. The method used was a randomized block design (RBD) with 5 treatments and 5 replications. Cabbage plants without insecticide treatment as control (P0), first treatment using synthetic insecticide (P1) Cypermethrin 50 EC 1.5 ml/L water (as comparison), second treatment using tobacco stem waste extract 30 ml/L, third treatment stem waste extract tobacco 40 ml/L and the fourth treatment of tobacco stem waste extract 50 ml/liter of water. The results showed that the treatment of tobacco stem waste extract at a concentration of 50 ml/L of water had a significant effect on reducing the intensity of P. xylostella attack. with the lowest level of damage of 13.60 % compared to control (P0). But not significantly different from the treatment using synthetic insecticides (P1).